论文部分内容阅读
目的研究结核分枝杆菌panD(Rv3601c)基因及其编码蛋白的结构和功能,为耐药结核的治疗提供参考依据。方法运用ClustalX 2.1、MEGA 6.06软件以及ExPASy、NCBI等在线工具分析结核分枝杆菌panD基因信息,同时分析其进化特征、编码蛋白质的理化性质、信号肽、磷酸化位点、结构特点并预测其功能;利用BepiPred 1.0Server和NetMHCIIpan 3.1Server预测panD蛋白的B细胞和T细胞抗原表位。结果结核分枝杆菌panD基因全长420bp,不同菌株panD基因序列相似度100%,具有高度同源性,进化关系较近,编码139个氨基酸。panD蛋白不稳定系数为8.72,亲水性平均系数为0.147,为稳定、疏水性蛋白、无跨膜区与信号肽,存在9个磷酸化位点。二级结构中以无规则卷曲为主,结构较疏松。三级结构同源建模成功。该蛋白具有多个潜在的B细胞抗原表位和T细胞抗原表位。结论panD蛋白作为脱羧酶,在结核分枝杆菌合成β-丙氨酸过程中具有重要作用。panD蛋白序列保守稳定,具有多个优势抗原表位,是治疗耐药结核的潜在新靶标。
Objective To study the structure and function of the Mycobacterium tuberculosis panD (Rv3601c) gene and its encoded protein and provide a reference for the treatment of drug-resistant tuberculosis. Methods The information of panD gene in Mycobacterium tuberculosis was analyzed by on-line tools such as ClustalX 2.1, MEGA 6.06, ExPASy and NCBI. The evolutionary characteristics, protein physical and chemical properties, signal peptide, phosphorylation sites and structural features were also analyzed. The B cell and T cell epitopes of panD protein were predicted using BepiPred 1.0Server and NetMHCIIpan 3.1Server. Results The Mycobacterium tuberculosis panD gene was 420 bp in length. The sequence similarity of the panD gene of different strains was 100%. The panD gene was highly homologous and had a close evolutionary relationship and encoded 139 amino acids. The panD protein instability coefficient was 8.72 and the average hydrophilicity coefficient was 0.147. It was a stable, hydrophobic protein with no transmembrane domain and signal peptide, and there were 9 phosphorylation sites. Secondary structure of random curl-based, loose structure. Three-level structure homology modeling success. The protein has multiple potential B cell epitopes and T cell epitopes. Conclusion The panD protein, as a decarboxylase, plays an important role in the synthesis of β-alanine from Mycobacterium tuberculosis. The conservative and stable panD protein sequence, with multiple dominant epitopes, is a potential new target for the treatment of drug-resistant TB.